Pressure-sensitive transfer sheets



June 1, 1965 w. REUTER 3,136,352

PRESSURE-SENSITIVE TRANSFER SHEETS Filed April 14. 1960 :5 Sheets-Sheet 1 Fig.7

7 PAPER TRANSFER QORGAIV/C cows/Iva MA r m? Fig.3 Fig.4

YfiEl/ERSE S/DE/ (FRO/VT SIDE SURFACE 6 w 9 WAXED AREA I N VE N TOR WALTER REUTER Affarnaya June 1, 1965 w. REUTER 3,186,862

PRESSURE-SENSITIVE TRANSFER SHEETS Filed April 14. 1960 3 Sheets-Sheet 2 Fig. 6

PAPER g/j/ 'P/GMENT Fig. 7

---vat. PARAFF/N PAPER I P/GMENT PARAFF/N PAPER BOTTOM IN VEN TOR WALTER REUTER By MM Afforneys June 1, 1965 w. REUTER 3,186,862

PRESSURE-SENSITIVE TRANSFER SHEETS Filed April 14, 1960 5 Sheets-Sheet 3 Fig.9

7 9 I PAPER \1 OLOR 01-09 20 Fig 70 22 79 WAX 52552 0m INVENTOR I WALTER REUTER Affomeys United States Patent 3,186,862 PRESSURE-SENSITWE TRANFER SI EETS Waiter Renter, Kappeler Strasse 174-173, Dusseidorf-Reisholz, Germany Filed Apr. 14, 196i Ser. No. 22,269 (Ilaims priority, application Germany, Apr. 17, 1959, R 25,339; Jan. 14, 1960, R 27,107; Feb. 11, 1969,

7 Claims. (Cl. 11736.4)

This invention relates to the preparation of sheets, especially paper, having a color-yielding layer, which can transfer script characters or color by stylus pressure onto another sheet having as especially prepared surface, without the use of any intermediate transfer papers. In addition, this invention also includes various physical embodiments of these sheets which have particular commercial uses.

The prior art contains many teachings pertinent to the manufacture of dual purpose transfer sheets. These products, however, in general, do not permit the production of a practicable number of copies. Furthermore, the c010.- yielding layer itself and the copies are not sufiiciently adhesive and cohesive, and consequently, the products smudge.

The principal object of the present invention, therefore, is to provide novel transfer sheets, wherein the coloryielding layer is smudge-proof, and wherein color is yielded upon pressure only to specially prepared surfaces.

Another object of this invention is to provide a color transfer sheet, wherein the color layer is masked by a thin film which eliminates any visual impression that the color layer is susceptible to smudgin g.

Still another object is to provide a dual purpose color transfer sheet, wherein one side is especially prepared to receive color, and wherein the other side is prepared to yield color.

Still another object of this invention is to provide a grating on the color-yielding layer to increase its coherence and adherence during and after use.

Upon further study of the specification, drawings and appended claims, other objects and advantages of the present invention will become apparent.

The accompanying drawings show several embodiments of the invention.

FIGURE 1 is a transfer sheet according to the invention in cross-section.

FIGURE 2 is a set consisting of several such sheets.

FIGURE 3 shows the reverse side of a transfer sheet as an example.

FIGURE 4 shows the front side as an example.

FIGURE 5 shows diagrammatically a telegraph roll with four usable paper transfers.

FIGURE 6 is a section through the uppermost sheet of a set of a telegraph roll according to FIGURE 5.

FIGURE 7 is a section through a sheet which lies under the first layer of a set of a telegraph roll according to FIGURE 5.

FIGURE 8 is a section through the last sheet of a writing set of a teletype machine according to FIGURE 5.

FIGURE 9 is a section through a script transfer sheet.

FIGURE 10 is a section through a sheet receiving script.

FIGURE 11 is a section through a script transfer sheet.

FIGURE 12 is a section through a script receiving sheet.

According to this invention, the color-yielding layer which is applied on the reverse side of the sheets and the color-receptive layer which is on the front side of the sheets are formed in a novel way so that the sheets which carry the ink layer on the reverse side do not yield their color to ordinary paper upon stylus pressure; by using specially prepared color-receptive sheets, however, one can reproduce script, drawings and the like in full sharpness. In addition, the coatings of the invention are formed in such a Way that they are substantially resistant to temperature, humidity, and light.

According to one mode of the invention, the coloryielding layer contains inorganic pigments such as, barium sulfate, chromic hydroxide, chromic oxide (green), chrome yellow, carbon black, ultramarine, titanium dioxide, sodium aluminum sulphate, and others or synthetic pigments such as milori blue. For the improvement of color, small quantities (about 12% by weight of inorganic pigment) of organic coloring matters, e.g. alizarin coloring substances, can be mixed in with binders. This coloryielding layer can also contain plastics, especially natural or synthetic resins, e.g. methyl cellulose in emulsion with natural or synthetic resins, rosin, abietic acid, pimaric acid, a kyd resins, or similar synthetic resins having binding properties. These plastics may also contain softeners or plasticizers.

This color-yielding layer can be applied fully or partly on the reverse side of the sheets in amounts of about 2 to 16 g./sq. m.-corresponding to thicknesses of about 0.005 mm. to 0.05 mm.

As another mode of the present invention, it has further been found that with respect to the color-yielding layers, that the use of inorganic coloring matter is not absolutely necessary, as organic coloring matter can be used exclusively. It is possible to obtain color-yielding layers with excellent color transferability by adding to the layer Water-soluble colloidal binders, cellulose esters, cellulose ethers and mixtures of such colloids. These colloids can be coagulated in any conventional manner, e.g. by the influence of a salt. If the coagulated material is not sufiiciently colored, it is possible to increase its color intensity by the addition of a coloring substance, preferably organic coloring matter. Coloring layers produced in such a way have excellent color intensity so that they yield very good copies under stylus pressure even when a large number of sheets are superimposed, e.g. 6 to 8 sheets. An excess of colloidal binders can preferably be used or the coagulation can be carried out only partly, or further colloidal binders, preferably synthetic resin mixtures of natural or synthetic resins and the like, can be added after coagulation.

If water is used as carrier of the dispersion, watersoluble salts will have to be used generally for coagulation. On the other hand, the binders used for the stabilization or selectivity of the color-yielding layer, e.g. colloidal synthetic resin salts, can be dispersed or dissolved in a different carrier.

With respect to the coloring matter utilized in a completely organic layer, it is possible to use organic pigments in conjunction with organic dyes, such as alizarin, or the latter can be used alone.

As softeners or plasticizers for the color-yielding layer the following substances, for example, can be used in small quantities: sulfon-ated neats-foot oil, phthalates, polyhydric alcohols like glycerine, glycols, and the like.

It has also been found out that by the addition of certain quantities or" other substances having a hardness similar to wax, for example, Waxes or wax-like substances (e.g. 2 to 15% or more of alcohol-soluble waxes, paraflin waxes, metallic soaps, stearates, mixtures of such ubstances with synthetic resin solutions or emulsions, etc.), a substmtial improvement is obtained in the sharpness of the transferred script without significantly decreasing either the transferabil-ity or adhesiveness of the color yielding layer.

According to the invention, the rheological properties of the medium in which the color-yielding layer is suspended is controlled by the use of suitable organic solvents, such as, benzene, aliphatic hydrocarbons, alcohols, esters, ketones, halogenated hydrocarbons and mixtures thereof. Upon the application of a coloring layer onto a sheet, the solvent evaporates, leaving a solidified adherent, srnu ge-resistant layer which yields its color only to specially prepared surfaces.

For the formation of the special color-receptive layer on the obverse surface of the sheets positioned underneath the uppermost sheet, substances having microcrystalline structure are particularly suitable. Such substances are, for example, wax-like substances, like ceresin, isoceresin or mixtures of such substances with parafiin, metal soaps or synthetic resins like polyisobutylene. It is also possible to use mixtures of synthetic resins with amorphous colorless or slightly colored bodies, like silicates and the like, which are embedded into the layer of synthetic resin. It is also noteworthy that this microcrystalline layer can be either colored or uncolored. Generally, the thickness of the specially prepared colorreceptive layer is about 0.002 mm. to about 0.015 mm.

The hardness of the color-yielding layer can be controlled by the addition of wax-like substances or mixtures of such substances with synthetic resin solutions or emulsions. A decrease in hardness, for example, can be obtained by an. increase in the wax content in the coloring layer to at least about to which addition, makes it possible to obtain color-yielding layers which, though suificiently adherent, can yield color to ordinary papers having untreated surfaces. It is necessary, therefore, to maintain a lower concentration of wax in the color-yielding layer.

The coagulation of the colloidal dispersion which is used for the formation of the coloring layer can be car: ried out as previously described by the addition of electrolytes, especially aqueous metal salt solutions. Coagulation can also take place by heating or adding oppositely charged colloids or by other measures by which the dispersed condition of the colloid contained in the layer is transferred into a non-soluble gel. The colloidal layer is, of course, made as thin as possible so that the coloring layer which has been produced by the simultaneously coagulated particles of a suitable synthetic resin solution is sufliciently coherent. The coagulated layer can, for example, be produced by coagulating a suitable aqueous colloidal solution (e.g. a glue solution or Water-soluble cellulose ester or ether) with an aqueous solution of aluminum sulphate, with the help of a positive aluminum hydroxide sol.

As colloids, within the scope of the present invention, it is possible to use, for example, lyophilic spherocolloids or linear colloids, e.g. solutions of cellulose esters, cellulose others, or mixture of lyophobic dispersion colloids, with sufiicient quantities of protective colloids or molecular colloids, respectively. As coagulating salts, it is possible, for example, not only to use alkali metal salts such as sodium salts, but also heavy metal salts such as lead salts, and the like.

The most important properties of the color-yielding layer resides in the fact that it is grip-fast and wipe-fast i.e. that it does not smudge in use and that the color cannot be transferred by stylus pressure onto ordinary paper but only onto a paper having a prepared surface. Although these properties are actually attained by both the color-yielding layers and the color-receptive layer disclosed in the present invention, the external appearance of the color-yielding layer gives one the impression that material can be rubbed off. Naturally, this appearance is a disadvantage from both the aesthetic and psychological standpoints.

To avoid this disadvantage, the present invention provides still another embodiment, wherein transfer sheets or rolls, as previously described, can be made insuch a way that they look like ordinary white or tinted sheets resins and copal resins and the like.

or rolls, whereas at the same time, the smudge-resistance of the color-yielding layer is increased, and the sharpness of transferred script is also improved.

This is accomplished by providing the sheets with a thin coating of a color-covering, preferably white or slightly colored covering layer which is adapted to the hue of the paper, and is both absolutely smudge-proof and waterproof. This covering layer can, for example, consist of a lacquer-like coating as obtained from watersoluble casein paints 'or other paint mixtures having synthetic resin vehicles. After drying, the films are both waterproof and smudge-proof. This color-covering layer can also be provided with suitable additive like liquid and solid plasticizers, natural resins, synthetic resins or mixtures thereof dissolved in suitable solvents. A thin covering layer imparts to the sheet a pleasing smooth appearance which hides the color-yielding layer so that there is no impression that such sheets cannot be used without the effects of smudging and smearing. This covering layer consisting of preferably white, or slightly tinted mixtures corresponding to the hue of the paper, is so thin that it is destroyed under stylus pressure. It has even been surprisingly found that sheets provided with such a color-covering layer yield an even sharper copy than sheets without it. Thereby it is also possible to use for the script transferring color layer, deeper color mixtures like deep black, deep blue, brown mixtures and the like which result in a sharpness of script on the color-receptive sheet which could not be obtained without such a covering layer.

To obtain the desired smudge-proof and waterproof properties of the layer, a wide variety of binders can be used, for example, casein, dextrin, mixtures of natural and synthetic resins, such as mixtures of polyvinyl The covering power or opacity of the outer coating can be obtained by the use of white pigments,-e.g. by titanium dioxide, zinc white, finely divided chalk and the like; or, the covering layer can be colored like the hue of the paper, by the addition of colored pigments. The incorporation of plasticizers and the like function to impart sufiicient elasticity to the covering layer so that it will not crack.

The described covering layers can be used with each type of color-yielding layer as long as the components of each layer are compatible with and do not react with one another.

The thinness of the covering layer can be varied in accordance with the composition of the layer. On the one hand. the cover layer must have such covering strength and must be applied in such a way that the color characters of the script yielding layer is completely covered, whereas, on the other hand, the white or colored covering layer must be so thin that it is completely destroyed under stylus pressure, especially the pressure exerted by typewriter keys, so that transferred characters appear in complete sharpness on the script receiving sheet. Generally, it is preferred to use about 16 g. of cover layer per square meter of sheet, which corresponds to a thickness of about 0.005 mm. to about 0.02 mm.

Papers provided with this covering layer can be used in all forms suitable for writing or printing, e.g. as rolls, telegraph rolls, addition rolls, punch-card rolls, and the like.

Other advantages are obtained from applying the colorcovering layer. It has, for example, been found that the color-yielding side of a transfer sheet can be printed upon with black, colored, or white characters. It is, therefore, now possible to provide this color-yielding layer with any desired patterns or pictorial designs, with descriptions, etc. In contrast, there was no such possibility with script and transfer copy papers of the prior art, since such papers could only be provided with printing on the obverse side; the color-yielding layer was not suitable for printing because of its dark colors, its consistency, and the likelihood that the uniformity and transferability of the layer would be deleteriously modified.

The colored printing which can be applied onto the color-covering layer can obviously appear in different forms. It can be a colored or pictorial coating, e.g. the imprint of a certain continuously repeated pattern or any pictorial or geometric design. (Naturally, if light colors are used in printing, this can add to the coloring effect of the covering layer.)

If a narrow grating-like pattern is printed on the colorcovering layer, when such a sheet is held against the light, the script of the copy cannot be seen on the colored side. Additionally, by the grating-like over-printing, the coloryielding layer does not become friable upon stylus pressure, so all remaining color particles are maintained in continuous cohesion in spite of some color transfer onto the prepared surface of a sheet underneath. By means of the grating, a protective net is superimposed on the color-covering layer of the color-yielding side and this ensures the continuous cohesion of the color layer even when one area of it has already been used for copying. It is, therefore, possible to use such a protected sheet much more often for copying than a sheet whose coloring layer is not so protected. Instead of applying a grating-like imprint onto the colorcovering layer, the color-covering layer itself can be applied in the form of a grating, preferably by printing. This technique yields substantially the same eifects as described above, and is also especially simple and advantageous.

If the color-covering layer itself is applied in the form of a grating, white or slightly colored lines appear on the black or very dark base of the coloring layer whereby the degree of brightness can be increased by a narrow grating. At any rate, a white or light colored grating removes the impression that the color-yielding is not smudge-proof.

If a grating is applied onto a White or lightly colored color-covering layer, the grating lines can be dark in color. In this case the impression of smudge-proof paper is made under all circumstances, regardless of the effects described above.

In general, the lines of the grating should be about from 0.1 mm. to 1.0 mm. in width, and the space in between them should be about 0.05 mm. to about 1.0 mm.

It is, of course, possible to make the brightening colorcovering layer in patterns or pictures other than in the form of a grating. It is advisable, however, in such a case, to make the patterns or other pictorial representations sufiiciently fine and to cover the color-yielding surface of the paper uniformly. The special advantage of the present invention lies in the fact that a color-yielding paper can now be provided with pictorial representations not only on the non-color side, as in the past, but also on the color side. These pictorial representations can also serve to make the color side easily distinguishable from the reverse side.

The sheets or foils, according to the invention, for making transfer copies have the advantage over other transfer copy methods in that no carbon or special intermediate transfer papers are needed. This is advantageous for the use of both rolls and multiple sheets since the insertion of carbon paper and subsequent removal thereof are not necessary.

Upon manufacture of the foils or sheets the coatings can be applied in any known manner, e.g. by spraying, rolling, etc.

The color application can cover the entire surface or only strips of the paper, likewise for the prepared front side. Additionally, it is also possible to avoid undesirable copies in certain areas by covering alternately the color-yielding or color-receptive side by suitable means, e.g. by overprinting.

The foils or sheets can be white or colored. It is thus possible to provide colored papers or colored sheets on the reverse side with a colored layer corresponding to the color of the paper so that the color preparation is not noticeable. An inadvertent interchanging of the sides of such foils can be avoided by providing one or both sides thereof with a suitable marking, preferably at the edge. It is also possible to mark in the described manner telegraph rolls at one or both longitudinal edges, which marks indicate the consumption of the roll.

An advantage of the method according to the invention is the extreme sharpness and good legibility of the transferred characters even with a large number of copies. Another advantage is that the transfer is possible at all temperatures. The color mixtures and color-receptive layers are temperature-proof, weather-proof and lightproof, which properties are important for use in the open air, in the tropics or Arctic countries.

The invention is particularly useful in the fabrication of rolls and manifolds. Since no carbon papers are used, the diameter of a telegraph roll is decreased considerably. Accordingly, it is possible to have much longer rolls with the same space as rolls interleaved with carbon papers. Similar advantages are obtained in the use of manifolds.

Referring now to the drawings indicated, the numeral 1 in FIGURE 1 indicates the transfer foil, e.g. a paper sheet. The reverse side of this paper sheet is covered with a layer 2 containing mixtures of inorganic pigments and/ or organic coloring matter with fillers and with natural or synthetic resins and plasticizers, wherein the proportions occur in certain ratios. The front side of sheet 1 is provided with a layer 3 receiving this color coating upon pressure transfer. This layer has been treated with microwaxes or microcrystalline wax mixtures (composition waxes) or with substances having similar properties.

According to FIGURE 2 several paper sheets of the type according to FIGURE 1 are united in a transfer set. The sheets can be interconnected at one edge of the set, e.g. by a glue edge 4 or by a binding. The uppermost sheet 5 is prepared only on the reverse side in the set shown in FIGURE 2. It can, however, also be prepared on the front side. The lowermost sheet of the set can only be prepared on the front side, although a color layer on the reverse side would not be deleterious.

According to FIGURE 3 the paper sheet has been coated only partly on its reverse side. The surfaces 6 do not transfer, whereas the areas 7 with the color mixture according to the invention, react to pressure.

According to FIGURE 4 it is also possible to apply wax onto certain parts of the front surface of the paper, e.g. in the areas 8 and 9, Whereas a central strip 10 and an area 11 are kept free of wax so that in these areas no script is transferred. The telegraph or teletype roll, according to FIGURES 5 to 8, consists only of usable paper strips 12, 13, 14 and 15 as distinguished from the known embodiments wherein carbon paper is interleaved. The reverse sides of strips 12, 13 and 14 are prepared with a layer 15, each, which layers transfer coloring matter upon exertion of stylus pressure onto a sheet positioned underneath which is prepared with a wax or paraffin layer 17. There is no transfer, however, onto ordinary writing paper. The upper surface of the uppermost sheet 12 can have a wax preparation or not, Whereas the upper sides of strips 13, 14 and 15 are provided in each case with a wax layer 17. The reverse side of the last sheet, 15, can be provided with or without a color layer.

One or both longitudinal edges of the strip 12 can have measuring markings 18 which indicate the degree of consumption of the roll.

In FIGURES 9 and 10 the numeral 19 is a sheet, a roll or another suitable foil; the numeral 20 is a grey color layer applied onto the paper and suitable for transfer, which layer is smudge-proof, coherent and waterproof. Onto this layer a thin layer of colored covering layer 21 has been applied which is also completely coherent, smudge-proof and waterproof because of a binder causing these properties, especially casein or plastic.

According to FIGURE 10, a script receiving layer 22 is applied onto the other side of sheet 19, which layer consists, for example, of waxes, wax mixtures, mixtures of wax and resin and the like.

FIGURE ll shows a paper script 23 or the like carrying a dark colored coloring layer 25.

The numeral 26 indicates a light colored covering layer. This layer carries pictorial representations, e.g. a grating 2'7.

According to FIGURE 12, a layer 28 has been applied onto that side of sheet 23 which receives the transferred characters. This layer may consist of waxes, wax mixtures, mixtures of wax and resin and the like. On the other side of sheet 23 a covering layer 29 and a covering layer 30 and a light-colored covering layer 30 are applied, the latter having the form of a grating in this case.

From the foregoing description of the invention, it is evident that many different components may be utilized in the manufacture of the various layers of the present invention. The invention lies broadly in the physical relation of suitable components, such as the binder and the pigment of the color-yielding (script-yielding) layer. The important criterion in this case is that upon stylus pressure, this layer will not yield color to ordinary untreated paper. Obviously, there is a Wide variety of pigmerits and binders that can be used to obtain this effect. Also, new synthetic resins and polymers, as well as new inorganic pigments, synthetic pigments and organic pigments are constantly being developed and made commercially available, many of which undoubtedly will be found adaptable as components of the color-yielding layer. The same applies also to the composition or" the colorreceptive layer and the color-covering layer. It is therefore, not only impossible to attempt a comprehensive catalogue of useful components, but to attempt to apprehend or describe the invention in its broader aspects in terms of the chemical names of the components used, would be misleading.

The following examples, consequently, are presented only as preferred embodiments of the present invention, and are not to be construed as limitative of the appended claims.

Example 1 To a sheet of paper having a thickness of about 0.05 mm., there is applied a color-yielding layer having a thickness of about 0.01 mm. and having the following composition which includes both inorganic and organic coloring matter:

Ingredient: Parts by weight, g.

Titanium dioxide 40-60 Alizarin blue 0.5-2

Vinyl chloride acetate in solution with ethyl acetate and ethyl alcohol 2-7.5

the synthetic resin having been dissolved at a ratio of 1:20 in the solvent.

Example 2 To a sheet of paper having a thickness of about 0.05

mm., there is applied a color-yielding layer having only organic coloring matter:

Parts by Ingredient: weight, g. Alizarin blue -10 Colloidal cellulose ether -20 Cobalt naphthenate 3 Example 3 To the sheet prepared in accordance with Example 1, a color-receptive layer is applied to the obverse side of said sheet, said color-receptive layer having a thickness of about 0.006 mm. and having the following composition:

Parts by Ingredient: weight, g. Ozocerite of about 79-82 solidification point 88 Parafiin of about 5052 solidification point 10 Polyisobutylene 2 Example 4 To the sheet prepared in accordance with Example 2, there is applied to the color-yielding layer a color-covering layer of about 0.005 mm., and having the following composition:

Parts by Ingredient: weight Casein 60-120 Water 350-750 Ammonia 3-12 Titanium dioxide 60-120 Carbolic acid 2-6 Non-drying oil 15-50 it is to be noted that each layer of the present invention is a normally solid, non-tacky megascopically homogeneous film.

It is understood that the inventor intends to claim, as a part of his invention, any variation, substitution and changes that lie within the scope of the invention and the hereinafter appended claims and intends to include within the scope of said claims such changes as may be apparent to those skilled in the art in the practice of the principles of this invention and within the scope as set forth in the hereinabove-stated specification.

What I claim is: V

1. A pressure-sensitive color-transfer sheet, consisting essentially of:

(a) a sheet of paper having two sides,

(b) a color-yielding layer of about 0.005 mm. to 0.05 mm. thickness superimposed on one side of said sheet of paper, said color-yielding layer comprising a dry megascopically homogenous film containing coloring matter and a non-rubbery, resinous binder selected from the group consisting of vinyl chloride acetate resins, alkyl resins, rosin, copal resin, cellulose ethers, cellulose esters, casein, abietic acid, and pimaric acid, said coloring matter comprising predominantly inorganic pigments and a small amount of organic pigments, said color-yielding layer being capable of transferring color to treated paper upon the exertion of stylus pressure, said color-yielding layer also being grip-fast and Wipe-fast,

(c) a smear-proof and water-proof color-covering layer of about 0.005 mm. to about 0.02 mm. thickness superimposed on said color-yielding layer, said colorcovering layer being of sufiicient thickness to substantially mask the color of the color-yielding layer and being suificiently thin so that upon the exertion of stylus pressure, it will break allowing color to be transferred from the color-yielding layer,

(d) a grating-like layer having lines of about 0.1 mm. to 1.0 mm. in width, the space between said lines being about 0.05 mm. to about 1.0 mm., said grating-like layer being imprinted on said color-covering layer, whereby the color-covering layer and the coloryielding layer are strengthened,

(e) a color-receptive layer of about 0.002 mm. to about 0.015 mm. thickness superimposed on the other side of said sheet of paper, said color-receptive layer consisting essentially of waxy substances having a microcrystalline structure.

2. The color-transfer sheet of claim 1 wherein the color-yielding layer comprises 40-60 parts by weight titanium dioxide, 0.5-2 parts by weight alizarin blue, and 2-7.5 parts copolymer of vinyl chloride and vinyl acetate, the color-covering layer comprises in parts by weight, 60-120 parts casein, 3-12 parts ammonia, 60-120 parts titanium dioxide, 2-6 parts carbolic acid, and 15-50 parts of a non-drying oil, and the color-receptive film comprises in parts by weight 88 parts ozocerite having a solidification point of 79-82 C., 10 parts paraffin having a solidification point of 50-52 C. and 2 parts polyisobutylene.

3. The color-transfer sheet of claim 1, wherein the resinous binder isa vinyl chloride acetate resin.

4. The color transfer sheet of claim 1, wherein the thickness of the paper is 0.05mm., the thickness of coloryielding layer is 0.01 mm., and the film comprises 40-60 parts by weight titanium dioxide, 0.5-2 parts by weight alizarin blue, and 2-7.5 parts copolymer of vinyl chloride and vinyl acetate.

5. The color transfer sheet of claim 1, wherein the thickness of the paper is about 0.05 mm., the thickness of the color-yielding layer is 0.01 mm., and the layer comprises 5-10 parts by Weight alizarin blue, -20 parts by weight colloidal cellulose ether, and 3 parts by Weight cobalt naphthenate.

6. The color transfer sheet of claim 1, wherein the color receptive film is 0.006 mm. thick and comprises in 10 parts by weight 88 parts ozocerite having a solidification point of 79-82 C., 10 parts paraffin having a solidification point of -52 C., and 2 parts polyisobutylene.

7. The color transfer sheet of claim 1, wherein the 1 color-covering layer is 0.005 mm. thick and comprises in parts by weight, -120 parts casein, 3-12 parts ammonia, 60-120 parts titanium dioxide, 2-6 parts carbolic acid, and 15-50 parts of a non-drying oil.

References Cited by the Examiner UNITED STATES PATENTS' 627,229 6/ 99 Foster 117--36-.6

680,637 4/01 Brown 28228 1,829,250 10/31 Walker 1l7-36 XR 1,864,097 6/32 Sherman 11736 2,279,604 4/42 Walti 11736 2,762,715 9/56 Newman 117-36,.4 2,872,340 2/59 Newman et al 117157 XR FOREIGN PATENTS 550,332 1/43 Great Britain.

RICHARD D. NEVIUS, Primary Examiner. 

1. A PRESSURE-SENSITIVE COLOR-TRANSFER SHEET, CONSISTING ESSENTIALLY OF: (A) A SHEET OF PAPER HAVING TWO SIDES, (B) A COLOR-YIELDING LAYER OF ABOUT 0.005 MM. TO 0.05 MM. THICKNESS SUPERIMPOSED ON ONE SIDE OF SAID SHEET OF PAPER, SAID COLOR-YIELDING LAYER COMPRISING A DRY MEGASCOPICALLY HOMOGENOUS FILM CONTAINING COLORING MATTER AND A NON-RUBBERY, RESINOUS BINDER SELECTED FROM THE GROUP CONSISTING OF VINYL CHLORIDE ACETATE RESINS, ALKYL RESINS, ROSIN, COPAL RESIN, CELLULOSE ETHERS, CELLULOSE ESTERS, CASEIN, ABIETIC ACID, AND PIMARIC ACID, SAID COLORING MATTER COMPRISING PREDOMINANTLY INORGANIC PIGMENTS AND A SMALL AMOUNT OF ORGANIC PIGMENTS, SAID COLOR-YIELDING LAYER BEING CAPABLE OF TRANSFERRING COLOR TO TREATED PAPER UPON THE EXERTION OF STYLUS PRESSURE, SAID COLOR-YIELDING LAYER ALSO BEING GRIP-FAST AND WIPE-FAST, (C) A SMEAR-PROOF AND WATER-PROOF COLOR-COVERING LAYER OF ABOUT 0.005 MM. TO ABOUT 0.02 MM. THICKNESS SUPERIMPOSED ON SAID COLOR-YIELDING LAYER, SAID COLORCOVERING LAYER BEING OF SUFFICIENT THICKNESS TO SUBSTANTIALLY MASK THE COLOR OF THE COLOR-YIELDING LAYER AND BEING SUFFICIENTLY THIN SO THAT UPON THE EXERTION OF STYLUS PRESSURE, IT WILL BREAK ALLOWING COLOR TO BE TRANSFERRED FROM THE COLOR-YIELDING LAYER, (D) A GRATING-LIKE LAYER HAVING LINES OF ABOUT 0.1 MM. TO 1.0 MM. IN WIDTH, THE SPACE BETWEEN SAID LINES BEING ABOUT 0.05 MM. TO ABOUT 1.0 MM., SAID GRATING-LIKE LAYER BEING IMPRINTED ON SAID COLOR-COVERING LAYER, WHEREBY THE COLOR-COVERING LAYER AND THE COLORYIELDING LAYER ARE STRENGTHENED, (E) A COLOR-RECEPTIVE LAYER OF ABOUT 0.002 MM. TO ABOUT 0.015 MM. THICKNESS SUPERIMPOSED ON THE OTHER SIDE OF SAID SHEET OF PAPER, SAID COLOR-RECEPTIVE LAYER CONSISTING ESSENTIALLY OF WAXY SUBSTANCES HAVING A MICROCRYSTALLINE STRUCTURE. 